[PATCH] swsusp: thaw userspace and kernel space separately
authorNigel Cunningham <ncunningham@linuxmail.org>
Thu, 7 Dec 2006 04:34:28 +0000 (20:34 -0800)
committerLinus Torvalds <torvalds@woody.osdl.org>
Thu, 7 Dec 2006 16:39:28 +0000 (08:39 -0800)
Modify process thawing so that we can thaw kernel space without thawing
userspace, and thaw kernelspace first.  This will be useful in later
patches, where I intend to get swsusp thawing kernel threads only before
seeking to free memory.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/freezer.h
kernel/power/process.c

index 266373f74445af8c4d5d112bd9492bc36e244039..294ebea859c99b51e79038921834b98ca6620bc2 100644 (file)
@@ -1,5 +1,8 @@
 /* Freezer declarations */
 
+#define FREEZER_KERNEL_THREADS 0
+#define FREEZER_ALL_THREADS 1
+
 #ifdef CONFIG_PM
 /*
  * Check if a process has been frozen
@@ -57,7 +60,8 @@ static inline void frozen_process(struct task_struct *p)
 
 extern void refrigerator(void);
 extern int freeze_processes(void);
-extern void thaw_processes(void);
+#define thaw_processes() do { thaw_some_processes(FREEZER_ALL_THREADS); } while(0)
+#define thaw_kernel_threads() do { thaw_some_processes(FREEZER_KERNEL_THREADS); } while(0)
 
 static inline int try_to_freeze(void)
 {
@@ -67,6 +71,9 @@ static inline int try_to_freeze(void)
        } else
                return 0;
 }
+
+extern void thaw_some_processes(int all);
+
 #else
 static inline int frozen(struct task_struct *p) { return 0; }
 static inline int freezing(struct task_struct *p) { return 0; }
index fedabad5a180243e36fd93741668c9c8aa44e265..cba8a5890eda822bbb1c2730ac2e5866e30e3ab3 100644 (file)
@@ -153,18 +153,29 @@ int freeze_processes(void)
        return 0;
 }
 
-void thaw_processes(void)
+void thaw_some_processes(int all)
 {
        struct task_struct *g, *p;
+       int pass = 0; /* Pass 0 = Kernel space, 1 = Userspace */
 
        printk("Restarting tasks... ");
        read_lock(&tasklist_lock);
-       do_each_thread(g, p) {
-               if (!freezeable(p))
-                       continue;
-               if (!thaw_process(p))
-                       printk(KERN_INFO "Strange, %s not stopped\n", p->comm);
-       } while_each_thread(g, p);
+       do {
+               do_each_thread(g, p) {
+                       /*
+                        * is_user = 0 if kernel thread or borrowed mm,
+                        * 1 otherwise.
+                        */
+                       int is_user = !!(p->mm && !(p->flags & PF_BORROWED_MM));
+                       if (!freezeable(p) || (is_user != pass))
+                               continue;
+                       if (!thaw_process(p))
+                               printk(KERN_INFO
+                                       "Strange, %s not stopped\n", p->comm);
+               } while_each_thread(g, p);
+
+               pass++;
+       } while (pass < 2 && all);
 
        read_unlock(&tasklist_lock);
        schedule();